This invention pertains to energy conservation apparatus, systems and methods for use in dwelling and office structures to reduce the heat load loss and heat load gain as a result of undesired heat energy transmission through windows or other energy transmission panel assemblies at the exterior surface of the structure. More particularly, the present invention pertains to selectively interposing a quantity of particulate insulating material in a cavity adjacent the window or transmission panel to block the heat energy transmission therethrough, and to removing the insulating material from the cavity to allow heat energy transmission therethrough under predetermined desirable conditions.
Systems which selectively fill and empty a window chamber or cavity between two energy transmission panels or windows in order to control the heat energy transmission therethrough are known in the art. The limited prior use and adaptation of such prior art systems have indicated a need for practical improvements and enhanced functional features.
Among other matters, certain prior art systems have evidenced only a limited effectiveness in quickly, completely and reliably filling and emptying the cavities of the energy transmission panel assemblies. Of course, incomplete control over filling and emptying the cavities tends to detract from the desirable insulative features available. Primary reasons for the limited effectiveness of such prior art systems are their relatively complex nature and an inefficient use of component elements. Such prior art systems typically require numerous components which are susceptible to unreliable operation and to failure. In some circumstances separate control devices are used to perform limited specific individual functions, resulting in duplication. For example, separate blowers are needed to create both vacuum and positive air flow to transport the insulating material in opposite directions. Prior art systems take the form of single integrated structural units wherein the blower and suction devices, the storage bins, the energy transmission panel assemblies, check valves, and the extensive plumbing are all structurally housed within a single unit. Such a single unit usually is very space-consuming, detracts from the interior design of the building because of its size, requires an oversized opening in the exterior wall of the building structure for installation, and has a relatively high cost per effective use area due to the large amount of equipment dedicated only to a single unit. Another form which prior art systems take is a plurality of transmission panel assemblies dispersed remotely from a single storage bin and blower and suction device. Insulating material from the single storage bin is dispersed to each of numerous energy transmission panel assemblies. Problems with this prior art embodiment have arisen typically because the building space consumed by the storage bin and blower and suction devices is relatively large, the distance over which the insulating material must travel between the single storage bin and the multiple panel assemblies is large thereby limiting the air transmission characteristics of the system, the effectiveness in emptying and filling a multiplicity of the cavities at the same time is limited due to a lack of precise control over each individual cavity, and the blower and suction devices and plumbing must have a significantly large capacity to transport the particulate insulating material over long distances to multiple panel assemblies. Other restrictive features of such prior art arrangements are appreciated by those skilled in this particular art.